Minimal Invasive Access Cavity PDF

Minimal Invasive Access Cavity  History Traditional access cavity: divergent Conservative access cavity: Ultraconservative access cavity (ninja): walls enabling Stainless steel file to convergent walls –(more remaining small hole–(more remaining...

Minimal Invasive Access Cavity  History Traditional access cavity: divergent Conservative access cavity: Ultraconservative access cavity (ninja): walls enabling Stainless steel file to convergent walls –(more remaining small hole–(more remaining tooth get directly straight into the canal tooth structure) structure) without fracture. Ultrasonic tips+ nickel titanium files Ultrasonic tips+ nickel titanium files Use (burs) + st.st files (Ni-Ti) (Ni-Ti) What do we need?? Magnification: loupe – microscope To get into the apical part of the tooth: which is the part with the most curvature – if infection is not removed in this part, then infection will get out of the apex causing spread of infection – bone resorption. Guided endodontic access Access formed by 3D construction (CBCT) of the tooth shape → guiding us toward the access cavity directly to preserve most of the tooth structure → avoid dangerous zone Problem with pulp horns In traditional: all pulp horns are included In conservative: not all ??? Advanced irrigation systems will disinfect the pulp horns with no need to open. 2 more types of access cavity Enter the access Enter the access through removal of through removal old restoration – to of caries preserve the tooth Minimal Invasive access cavity 2 Stress and fracture For this reason, for any conservative preparation → flexible files must be used Nickle titanium files. Not stainless steal files Advnced irrigation system What happens after access cavity??? Loss of tooth structure → loss of structural integrity, according to the size of the cavity Marginal ridges are considered the most important key factor for strength Small access cavity → loss of strength by 5% Loss of one of marginal ridges: 21% loss MOD: 2 marginal ridges: 63% loss What causes the tooth to fracture after endodontic treatment?? Brittleness due to loss of dentin elasticity after dehydration → No Due to loss of structure integrity → yes What causes loss of structural integrity? Access cavity Loss of dentin minerals by irrigation Loss of dentin due to drilling for post and core Biological success Factors necessary for structural integrity: 4 mm above bone – 4 mm below bone 2 mm above bone – parallel in at least 3 walls Modern instruments: CK endodontic access bur for ultraconservative access cavity Ultrasonic tips SAF: self adjusting file → used in mechanical and biological removal of debris and bacteria → has unit of irritant